Hopefully the spotters/doctor just saw the head hit and took him out as a precaution, and he doesn't actually have a concussion.
Just getting up slowly after a head hit is enough to pull a player out for further testing. if he passed the test he would be able to come back. Here's a list of reasons a player gets pulled.
"The new protocol requires that the player be evaluated by a physician if he exhibits any of the following:
Loss of consciousness
Motor incoordination/balance problems
Slow to get up following a hit to the head
Blank or vacant look
Disorientation
Clutching the head after a hit
Visible facial injury in combination with any of the above
The physician will perform the evaluation in “…a quiet place free from distraction†(i.e. not the bench), and will use a standardized assessment tool – the NHL SCAT 2 (sports concussion assessment tool)."
from
http://obia.ca/new-nhl-concussion-guidelines-lets-get-the-doctor-involved/
It is weird though. It seems any medical personnel placed in that role or any official can put players into protocol, but it also says the suspected player may not return until approved by his team's doctor. I don't know if that's an oversight in wording and any of the doctors can pass him, or if it really means only the players team doctors can approve it. It seems like a pretty big loophole if there's a dozen people who can pull a player out of a game, but only the team doctor, that doesn't travel with the team all the time, can ok them to come back.